How to Hide Manga+Press Comic Manager Admin Menus

function plt_hide_mangapress_menus() {
	//Hide "Settings → Manga+Press Options".
	remove_submenu_page('options-general.php', 'mangapress-options-page');

	//Hide "Comics".
	remove_menu_page('edit.php?post_type=mangapress_comic');
	//Hide "Comics → Comics".
	remove_submenu_page('edit.php?post_type=mangapress_comic', 'edit.php?post_type=mangapress_comic');
	//Hide "Comics → Add New Comic".
	remove_submenu_page('edit.php?post_type=mangapress_comic', 'post-new.php?post_type=mangapress_comic');
	//Hide "Comics → Series".
	remove_submenu_page('edit.php?post_type=mangapress_comic', 'edit-tags.php?taxonomy=mangapress_series&post_type=mangapress_comic');
}

add_action('admin_menu', 'plt_hide_mangapress_menus', 11);
Where do I put this code?